release: v0.2.0 — switch smarm to the pinned v0.5.0 git tag

The gen_server API port itself already landed upstream (078072b, tracking
smarm HEAD efbc254 pre-git-dep). This just moves the dependency off the
local path checkout onto the git remote, pinned to the smarm v0.5.0
release tag (a03a7ca) rather than a floating branch HEAD.

Verified: 90 lib + 45 integration + 2 doc tests green, examples build,
under default and --all-features.

Cargo.toml

@@ -1,12 +1,12 @@
 [package]
 name = "urus"
-version = "0.1.0"
+version = "0.2.0"
 edition = "2021"
 rust-version = "1.95"
 description = "Cowboy/bandit-style HTTP library for the smarm actor runtime"
 
 [dependencies]
-smarm    = { path = "../smarm" }
+smarm    = { git = "https://git.kalsbeek.dev/Markk116/smarm", tag = "v0.5.0" }
 httparse = "1.9"
 libc     = "0.2"
 sha1_smol = "1"